echo "Please input one month:"
read month1
case "$month1" in  # 类似switch结构
1)
  echo "The month is Jan";;
2)
  echo "The month is Feb";;
3)
  echo "The month is Mar";;
4)
  echo "The month is Apr";;
5)
  echo "The month is May";;
6)
  echo "The month is Jun";;
7)
  echo "The month is Jul";;
8)
  echo "The month is Aug";;
9)
  echo "The month is Sep";;
10)
  echo "The month is Oct";;
11)
  echo "The month is Nov";;
12)
  echo "The month is Dec";;
*)
  echo "The month is not a month";;
esac
exit 0
